Differentiation characteristics of the 46° halo and the supralateral arc

Common properties
These features normally are appropriate to identify the halo in the 46° region; if the halo still cannot be determined exactly by these properties, then also check the criteria for the corresponding Sun elevation

• Halo is poorly coloured (in most cases, just red, orange and white are visible)
• No tangent arcs to the 22° halo visible, or they are significantly fainter than the 22° halo
• No infralateral arc visible

• Halo is colourful (blue and green are also visible)
• Tangent arcs are visible, but no 22° halo, or 22° halo is very much fainter than the tangent arcs
• Supralateral arc always touches the circumzenithal arc (keep in mind that at Sun elevations between 15° and 27° also the 46° halo touches the circumzenithal arc)
• Infralateral arc is visible

• 22° halo and tangent arcs are of similar brightness or both are well recognizable
• Halo in the 46° region has two sections that are significantly different: colourful and colourless or brighter and fainter parts
• Good displays show up both haloes simultaneously
• Infralateral arc may be visible

Sun elevation less than 15°
Supralateral arc touches 46° halo at its sides; if the Sun is near the horizon, contact arcs are at the same elevation as the Sun

• Gap between 46° halo and circumzenithal arc
• Only the upper part of the halo is visible

• Halo is visible at both sides only, but symmetrically

• Very colourful or bright section at both sides of the 46° halo

Sun elevation between 15° and 27°
Identification of both halo results difficult as both haloes overlap

• Touches circumzenithal arc

• Touches circumzenithal arc

• Haloes are very similar to each other; use also Common properties

Sun elevation between 27° and 32°
Haloes do not touch themselves

• Gap between 46° halo and circumzenithal arc

• Distance from Sun is more than 46°

• Bright and colourful section of a halo above 46° halo
• Two separate haloes can be distinguished well

Sun elevation more than 32°
Supralateral arc does not exist at Sun elevations of more than 32°

• Halo in 46° region is always a 46° halo

• Not possible

• Not possible